title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=133 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Nutrient cycling characteristics along a chronosequence of forest primary succession in the Hailuogou Glacier retreat area, eastern Tibetan Plateau link: https://peerj.com/articles/18867 last-modified: 2025-01-31 description: BackgroundThe Hailuogou Glacier has been continuously retreating since the end of the Little Ice Age, resulting in a 125-year soil chronosequence and a complete primary forest succession sequence. Nutrient cycling and utilization are the foundation to forest succession processes and dynamic changes, directly influencing the structure and stability of ecosystems. However, our understandings on the characteristics of ecosystem nutrient accumulation and recycling during succession, especially in the context of primary succession within glacier retreat areas, remain limited. To address this, we investigated nutrient characteristics across six forest primary succession sites in the Hailuogou Glacier retreat area.MethodsSix sites representing three forest stages: the pioneer plant stage (S1), the broad-leaved forest stage (S2–S4), and the coniferous forest stage (S5–S6). Three quadrats were established at each site, and measurements of biomass as well as soil characteristics were documented within each quadrat. Subsequently, we collected samples of vegetation, soil and litter. By measuring the concentrations of N, P, K, Ca, and Mg in vegetation and soil and combining with the data of the quadrat survey, the pools and nutrient characteristics of N, P, K, Ca, and Mg in various components of the ecosystem were calculated at each site.ResultsOur findings indicated that: (1) Nutrient pools, excluding the soil C layer, increased with forest primary succession, reaching 5,995.71 kg hm−2 N, 461.83 kg hm−2 P, 3,798.09 kg hm−2 K, 7,559.81 kg hm−2 Ca and 1,948.13 kg hm−2 Mg at site S6; however, the pools of P, K, and Mg in the Oa layer, and Ca and Mg in the tree layer, attained their peak levels at sites S3 to S4. (2) The pools of N, Ca, and Mg in the organic soil were significantly greater than vegetation. Although over 60% of the P and K were stored in the organic soil at site S1, these proportions shifted, with vegetation holding 60.71% of P and 56.86% of K at site S5. (3) Broad-leaved forests exhibited higher nutrient return, cycling, and absorption, thereby accelerating nutrient circulation and depleting soil nutrients to maintain growth. In contrast, coniferous forests were more efficient at nutrient utilization and storage, retaining nutrients and maintaining high biomass and productivity in nutrient-poor environments. Overall, these findings highlighted that the nutrients in each component of the ecosystem continue to accumulate with forest primary succession. Coniferous forests’ nutrient cycling mechanisms offer a competitive edge in nutrient-poor environments, enhancing ecosystem stability. creator: Danli Yang creator: Ji Luo creator: Shumiao Shu creator: Yan Hu creator: Hongsong Tang creator: Xuemei Li uri: https://doi.org/10.7717/peerj.18867 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Yang et al. title: A narrative review on the role of cognition, nutrition and energy availability in athletes of competitive sports to combat RED-S link: https://peerj.com/articles/18849 last-modified: 2025-01-31 description: BackgroundIn the present scenario, competitive sports require athletes to achieve a phenomenal balance between cognitive abilities, motor skills, nutritional intake, and energy deficiencies. Such stability would enable the athletes to excel in their sporting field. Evidence shows that athletes develop specific cognitive abilities based on their sporting field. Nutrition is vital in creating an athlete’s cognitive ability and physical needs required to participate in competitive sports. The reduction in the intake of nutrients required before, after and during sports participation could result in relative energy deficiency in sports (RED-S), affecting the parts of the body.MethodsThe rationale behind the survey is to understand the role of nutrition and energy deficiency on the athletes’ cognitive abilities. The review’s research areas were identified as athletes’ cognition and nutrition in the context of RED-S. Search keywords were found based on the research area, such as “cognitive”, “nutrition”, and “energy deficiency/availability” in athletes. The search keywords were combined to form search queries (SQs). SQs were used to carry out the search on the Web of Science and Scopus databases.ResultsSports play an important role in athletes’ cognitive abilities, such as decision-making, attention, memory, etc. Nutritional intakes, such as caffeinated, carbohydrate, alkaline, and protein-based supplements and diets, also significantly affect athletes’ cognitive and motor abilities. Low energy availability (LEA) causes cognitive and physical health problems in both female and male athletes.ConclusionThe review identified that nutrition and LEA play crucial roles in athletes’ cognitive performance. Deficits in nutritional intake and energy availability lead to RED-S. Hence, cognitive performance could be used as an early indication to identify the nutritional and energy deficits in advance, enabling athletes to combat RED-S. creator: Subalatha M. creator: Dhanush Rachaveti creator: Amutha S. creator: Ponpandi M. uri: https://doi.org/10.7717/peerj.18849 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 M et al. title: Relationships among COVID-19 causal factors perceived by children, basic psychological needs and social anxiety link: https://peerj.com/articles/18828 last-modified: 2025-01-31 description: BackgroundThe pandemic caused by COVID-19 had a great impact on our society as the lives of children have been affected, as well as their psychological health and social anxiety.ObjectiveTo examine whether COVID-19 causal factors perceived by children predicted basic psychological needs and social anxiety, and if basic psychological needs predicted social anxiety.MethodsA sample of 58 schoolchildren (Mage = 10.18; SD = 0.77; 36 boys, 22 girls) participated in the study and completed a series of self-report measures. The relationship between the study variables was examined using partial least square path modelling (PLS-PM).ResultsSocial distancing and protection were found to significantly reduce competence satisfaction. Perceived psychological impact significantly negatively predicted relatedness satisfaction and significantly positively autonomy frustration and competence frustration. Perceived psychological impact significantly negatively predicted anxiety in the interaction with the opposite sex. Autonomy satisfaction significantly positively predicted anxiety in the interaction with the opposite sex. Autonomy frustration significantly positively predicted anxiety in public speaking interaction with teachers, significantly positively anxiety in the interaction with the opposite sex, significantly positively anxiety of being embarrassed or ridiculed and significantly positively anxiety in the interaction with strangers.ConclusionPerceived psychological impact was the causal factor that revealed a higher impact on basic psychological needs. As such, it is important to take measures with children in pandemic situations to minimize this variable. On the other hand, Autonomy frustration revealed a higher impact on social anxiety. Thus, it is necessary to emphasize autonomy in children respecting the restrictions imposed to minimize the impact of social anxiety. creator: Higinio González-García creator: Leandro Álvarez-Kurogi creator: Joel Prieto Andreu creator: Javier Tierno Cordón creator: Rosario Castro López creator: Jesús Salas Sánchez uri: https://doi.org/10.7717/peerj.18828 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 González-García et al. title: Effects of drought stress and Morchella inoculation on the physicochemical properties, enzymatic activities, and bacterial community of Poa pratensis L. rhizosphere soil link: https://peerj.com/articles/18793 last-modified: 2025-01-31 description: BackgroundSoil microorganisms are crucial for plant growth, and both plants and their associated rhizosphere microbes are impacted by changes in soil moisture. Inoculation with beneficial fungi can improve bacterial community structure and soil parameters.AimUnder drought stress conditions, the effects of inoculation with Morchella on the physicochemical properties, enzyme activity, and bacterial community structure of the rhizosphere soil of Poa pratensis were studied.MethodsHigh-throughput sequencing was employed to study rhizosphere soil bacterial communities in both Morchella-inoculated and uninoculated Poa pratensis rhizosphere soil subjected to moderate (50% soil moisture) and severe (30% soil moisture) drought stress, as well as under normal water conditions (70% soil moisture).ResultsMorchella inoculation significantly increased the alkaline nitrogen (AN) and available phosphorus (AP) contents, protease activity (PA), and alkaline phosphatase activity (APA) of Poa pratensis rhizosphere soil. Both Morchella inoculation and drought stress significantly altered the abundance and diversity of the P. pratensis rhizosphere community. The Chao1, Shannon, and Pielou diversity indices decreased with increasing drought stress. The effect of Morchella inoculation was improved under moderate drought stress and unstressed conditions. In addition, Morchella inoculation may help to stabilize the rhizosphere bacterial community under various levels of soil moisture. creator: Wei Yin creator: Le Wang creator: Qian Han Shang creator: Yi Xin Li creator: Wei Sa creator: Quan Min Dong creator: Jian Liang uri: https://doi.org/10.7717/peerj.18793 license: https://creativecommons.org/licenses/by-nc/4.0 rights: © 2025 Yin et al. title: Three new species of the spider genus Naphrys Edwards (Araneae, Salticidae) under morphology and molecular data with notes in the distribution of Naphrys acerba (Peckham & Peckham) from Mexico link: https://peerj.com/articles/18775 last-modified: 2025-01-31 description: Herein, we describe three new species of the spider genus Naphrys Edwards, 2003 from Mexico: Naphrys echerisp. nov., Naphrys tecoxquinsp. nov., and Naphrys tuucasp. nov. An integrative taxonomic approach was applied, utilizing data from morphology, ultra-morphology, the mitochondrial gene COI, and distribution records. Four molecular methods for species delimitation were implemented under the corrected p-distance Neighbor-Joining (NJ) criteria: (1) Assemble Species by Automatic Partitioning (ASAP); (2) general mixed Yule coalescent (GMYC); (3) Bayesian Poisson tree process (bPTP); and (4) multi-rate Poisson tree process (mPTP). Both morphological and molecular data supported the delimitation and recognition of the three new species. The average interspecific genetic distance (p-distance) within the genus Naphrys is 14%, while the intraspecific genetic distances (p-distance) is <2% for most species. We demonstrate that the natural distribution of Naphrys is not restricted to the Nearctic region. Furthermore, the reported localities herein represent the first with precise locations in the country for Naphrys acerba. In addition, a taxonomic identification key is provided for the species in the genus. creator: Juan Maldonado-Carrizales creator: Alejandro Valdez-Mondragón creator: María L. Jiménez-Jiménez creator: Javier Ponce-Saavedra uri: https://doi.org/10.7717/peerj.18775 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Maldonado-Carrizales et al. title: Harnessing the potential of chloroplast-derived expression elements for enhanced production of cellulases in Escherichia coli link: https://peerj.com/articles/18616 last-modified: 2025-01-31 description: Thermophilic cellulases can play a crucial part in the efficient breakdown of cellulose—a major component of lignocellulosic plant biomass, however, their commercial production needs simple and robust biomanufacturing biosystems. In this study, two cellulases (β-glucosidase and endoglucanase) were heterologously expressed in Escherichia coli under a chloroplast-derived constitutive promoter and expression-enhancing terminator. The genes encoding the cellulases were sourced from a thermophilic bacterium Thermotoga maritima to exploit their industrially needed thermotolerance potential. The codon-optimized gene sequences were synthesized and placed under a tobacco chloroplast 16S rRNA promoter (Prrn), along with the 5′ UTR (untranslated region) from gene 10 of phage T7 (T7g10). A six-residue long histidine tag (His6-tag) was attached to the N-terminus for protein detection. A high-level of expression of β-glucosidase and endoglucanase in E. coli was recorded from the chloroplast promoter and terminator. Furthermore, the activity assays confirmed that the recombinant enzymes maintained their activity at elevated temperatures. Thermostability analysis showed that recombinant enzymes retained their thermotolerance even after being expressed in a non-native host. Where, β-glucosidase and endoglucanase showed their optimum activities at 90 °C and 100 °C, respectively. Examination of the 3D structures of T. maritima cellulases revealed differential ionic interactions contributing to this high degree of thermotolerance. The study highlights the feasibility of producing thermostable versions of recombinant enzymes in E. coli at high levels. Our finding underscores the potential of this approach to meet industrial demands for efficient enzyme production employing E. coli as a robust biomanufacturing platform. creator: Ayesha Siddiqui creator: Muhammad Mudassar Iqbal creator: Asad Ali creator: Iqra Fatima creator: Hazrat Ali creator: Aamir Shehzad creator: Sameer H. Qari creator: Ghulam Raza creator: Muhammad Aamer Mehmood creator: Peter J. Nixon creator: Niaz Ahmad uri: https://doi.org/10.7717/peerj.18616 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Siddiqui et al. title: Life expectancy of cats in Britain: moggies and mollies live longer link: https://peerj.com/articles/18869 last-modified: 2025-01-30 description: The domestic cat (Felis catus) has been a popular companion animal for about 12,000 years, initially valued for rodent control before evolving into pets that provide affection and companionship. Unlike dogs, cats were not selectively bred for specific roles until the late 1800s, resulting in breeds defined primarily by appearance, which sometimes leads to genetic disorders. Modern animal welfare concerns emphasize longevity and health, prompting research into factors affecting cat lifespans, including sex, reproductive status, and breed. This study aims to expand on previous UK research by analyzing these interactions and highlighting the potential negative impacts of pure breeding on cat health. Data from 7,708 cats receiving veterinary care in the UK during 2019 were analyzed, focusing on reproductive status, breeding status, age at death, and sex. Data were analyzed using ANOVA and Cox proportional hazards models to assess survival differences. The overall mean lifespan of cats in the UK is 11.83 years. Analysis indicates that male cats live shorter lives than females, attributed to higher trauma rates and health issues among males. Neutered/spayed cats generally exhibit longer lifespans compared to entire cats. Tom cats have the shortest lifespan, while spayed females (mollies) live the longest. Moggies tend to outlive both pure and cross-bred cats, suggesting that genetic diversity may contribute to greater longevity. The results of this study emphasize the influence of sex, reproductive status, and cat type on feline lifespan, highlighting the need for targeted health interventions, particularly for male cats. The findings underscore the complex interplay of genetic and environmental factors in determining the health and longevity of domestic cats. This research not only contributes to existing knowledge but also advocates for the consideration of these variables in future studies and veterinary practices. creator: Fernando Mata uri: https://doi.org/10.7717/peerj.18869 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Mata title: Prediction of influenza A virus-human protein-protein interactions using XGBoost with continuous and discontinuous amino acids information link: https://peerj.com/articles/18863 last-modified: 2025-01-30 description: Influenza A virus (IAV) has the characteristics of high infectivity and high pathogenicity, which makes IAV infection a serious public health threat. Identifying protein-protein interactions (PPIs) between IAV and human proteins is beneficial for understanding the mechanism of viral infection and designing antiviral drugs. In this article, we developed a sequence-based machine learning method for predicting PPI. First, we applied a new negative sample construction method to establish a high-quality IAV-human PPI dataset. Then we used conjoint triad (CT) and Moran autocorrelation (Moran) to encode biologically relevant features. The joint consideration utilizing the complementary information between contiguous and discontinuous amino acids provides a more comprehensive description of PPI information. After comparing different machine learning models, the eXtreme Gradient Boosting (XGBoost) model was determined as the final model for the prediction. The model achieved an accuracy of 96.89%, precision of 98.79%, recall of 94.85%, F1-score of 96.78%. Finally, we successfully identified 3,269 potential target proteins. Gene ontology (GO) and pathway analysis showed that these genes were highly associated with IAV infection. The analysis of the PPI network further revealed that the predicted proteins were classified as core proteins within the human protein interaction network. This study may encourage the identification of potential targets for the discovery of more effective anti-influenza drugs. The source codes and datasets are available at https://github.com/HVPPIlab/IVA-Human-PPI/. creator: Binghua Li creator: Xin Li creator: Xiaoyu Li creator: Li Wang creator: Jun Lu creator: Jia Wang uri: https://doi.org/10.7717/peerj.18863 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Li et al. title: Serum salusin levels in diarrhea- and constipation-predominant irritable bowel syndrome link: https://peerj.com/articles/18859 last-modified: 2025-01-30 description: ObjectiveInflammation and immunity play major roles in the etiopathogenesis of functional intestinal disorders. The salusins that were identified in this study are important because of their ease of collection, sensitivity and reliability. For that reason, the aim of this study was to analyze the importance of the levels of salusin in the blood, an inflammation-related parameter, in the diagnosis and prediction of irritable bowel disease.MethodologyThe study participants included 28 diagnosed with constipation-predominant IBS, 29 (34.1%) diagnosed with diarrhea-predominant IBS (D-IBS), and 28 (32.9%) controls. Enzyme-linked immune-sorbent assay (ELISA) method has been used for the measurement of salusin levels.ResultsParticipants were 50 (58.8%) female and 35 (41.2%) male. The serum levels of salusin-α were substantially reduced in the diarrhea-predominant IBS group vs controls. There was also no major difference in the levels of salusin between the constipation-predominant-IBS and the diarrhea-predominant IBS group.ConclusionA major prognostic relationship was found between the level of salusins and the subgroup of D-IBS. It is well known that salusins have been related to inflammatory processes and oxidative injury in previous studies. The relationship between salusin and gastrointestinal diseases should be further investigated. Low-grade submucosal intestinal inflammation is also associated with irritable bowel syndrome. It is our belief that salusins may be useful in diagnosing, predicting or treating IBS. creator: Elif Tugba Tuncel creator: Seda Sabah Ozcan creator: Mehmet Korkmaz creator: Elif Börekci uri: https://doi.org/10.7717/peerj.18859 license: https://creativecommons.org/licenses/by-nc/4.0 rights: © 2025 Tuncel et al. title: Acidity, sugar, and alcohol contents during the fermentation of Osmanthus-flavored sweet rice wine and microbial community dynamics link: https://peerj.com/articles/18826 last-modified: 2025-01-30 description: Sweet rice wine is a popular traditional Chinese rice wine widely loved by Chinese people for its high nutritional value. Osmanthus flower petals contain various nutrients and have good medicinal value. However, the dynamics of the sugar level, acidity, alcohol content, and microbial community during the fermentation of Osmanthus-flavored sweet rice wine have not been evaluated, which can lead to the unstable quality of Osmanthus flower sweet rice wine (OFSRW). In this study, the dynamic changes in sugar level, acidity, alcohol content, microbial community composition, and microbial metabolic pathways during traditional fermentation of OFSRW at four-time points—0 h (AG0), 24 h (AG24), 36 h (AG36), and 43 h (AG43)—were analyzed via direct titration, total acid assays, alcoholometry, and high-throughput macrogenomic techniques. First, we found that bacteria were the dominant microorganisms in the early stage of OFSRW fermentation (AG0), fungi were the dominant microorganisms in the middle and late stages of fermentation (AG24 and AG36), and Rhizopus was the main fungal genus throughout fermentation. Acidity and total sugars increased with fermentation time, and alcohol was not detected until the end of fermentation. Diversity analysis revealed that the dominant species at the beginning of natural fermentation was A. johnsonii, and R. delemar became the dominant species as natural fermentation progressed. Metabolic pathway analysis revealed that energy production and conversion, carbohydrate transport, amino acid transport, and metabolic pathways were the most active metabolic pathways in the fermenter. These results provide a reference basis for changes in the microbial community during the fermentation of cinnamon-flavored sweet rice wine. creator: Ping Tian creator: Jiaqiong Wan creator: Tuo Yin creator: Li Liu creator: Hongbing Ren creator: Hanbing Cai creator: Xiaozhen Liu creator: Hanyao Zhang uri: https://doi.org/10.7717/peerj.18826 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Tian et al.